Gas injection valve and filling jig used for filling gas

ABSTRACT

A gas spray valve permits easy recharging of gas containers after use. The gas spray valve is of considerable strength and rigidity and can be manufactured in a less costly manner. One of the openings of a gas conduit  111  of a valve pin  104  is positioned so that, when the valve pin  104  is in the raised position, the opening is positioned above a second seal ring  108  and, when the valve pin  104  is pushed into a first and second stop position, the opening is positioned below the second seal ring  108.    
     A gas supply passage  118  is provided that connects the interior of a gas container  102  with a metering chamber  110  on the inside of a first seal ring  106  only when the valve pin  104  is in the raised position. When the valve pin  104  is pushed into a second stop position, the portion with smaller diameter  104   a  of the valve pin  104  is pushed down below the first seal ring  106  so that the interior of the gas container  102  communicates with the metering chamber  110  and the gas conduit  111 . This permits recharging of the gas container with the gas.

TECHNICAL FIELD

[0001] The present invention relates to a gas spray valve for sprayingcontents of a gas container with the help of high-pressure gas as apropellant, such as liquid carbon dioxide, and more particularly, to animproved gas spray valve that permits reuse of gas containers.

BACKGROUND ART

[0002] One type of spray apparatus has traditionally been used thatoperates by spraying the contents of a gas container, such as a medicalagent, with the help of high-pressure gas loaded in the containertogether with the contents. In such spray apparatuses, the gas issprayed through a gas spray valve secured to an opening portion of thegas container. These spray apparatuses use certain types ofchlorofluorocarbons as the propellant. In view of recent concerns aboutenvironmental protection, however, newly developed spray apparatusesthat make use of HFC-134a, an alternative to chlorofluorocarbon, arebecoming increasingly common in the marketplace.

[0003] Although HFC-134a has substantially no effects on the ozonelayer, it has a significant impact on the global warming, 1,000 timesmore significant than the impact of C0 ₂, or even worse. Therefore, afuture increase in the use of HFC-134a is expected to pose a newproblem. For this reason, it is proposed to use other propellants forspray apparatuses that have less effects on the ozone layer destructionor global warming, including carbon dioxide, gaseous nitrogen, and inertgases such as helium, neon, krypton, xenon, and radon.

[0004] It is desired that these gases, as with the hydrofluorocarbonscurrently in use, be liquefied when used as a propellant for use inspray apparatuses in order to make the gas container small. For example,liquid carbon dioxide has a vapor pressure of 60 kgf/cm² at 20° C. It isalso preferred in terms of volume efficiency that the inert gases alsobe highly pressurized or liquefied and thus be put under a pressure of50 kgf/cm² or greater.

[0005] Handling such high-pressure gases requires a specially designedgas spray valve, such as the one described in Japanese Patent Laid-OpenPublication No. Hei 8-141450.

[0006] As shown in FIG. 9, this gas spray valve includes a valve case 2secured to an opening portion la of a gas container 1 and a valve pin 3slidably received in the valve case 2. A first seal ring 4 and a secondseal ring 5 are arranged within the valve case 2 and are axially spacedapart from each other. A metering chamber 6 is formed between the sealrings 4 and 5 for trapping a predetermined amount of the gas prior tospraying. The valve pin 3 includes on the lower end thereof a firstvalve portion 7 that comes into close contact with the first seal ring 4when the valve pin 3 is pushed in from the outside. The valve pin 3 alsoincludes on the upper end thereof a second valve portion 8. The secondvalve portion 8 consists of a portion with larger diameter 8 a thatcomes into close contact with the second seal ring 5 when the valve pin3 is in its upper position and a portion with smaller diameter 8 b thatdefines a gap together with the second seal ring 5 when the valve pin 3has been pushed in from the outside. The metering chamber accommodates aspring 9, which always urges the valve pin 3 upward.

[0007] When the gas spray valve constructed in the above-describedmanner is in its steady state without the valve pin 3 being pushed fromthe outside, the first valve portion 7 is apart from the first seal ring4 with the large portion 8 a of the second valve portion 8 remaining inclose contact with the second seal ring 5, such that the interior of thegas container 1 remains in communication with the metering chamber 6. Asthe valve pin 3 is pushed in from the outside, the first valve portion 7comes into close contact with the first seal ring 4, followed byformation of a gap between the small portion 8 b of the second valveportion 8 and the second seal ring 5. The gap allows the contents of thegas container 1 to pass through along with the gas. The contents and thegas are then sprayed out from the gas container 1. Since formation ofthe gap between the second valve portion 8 and the second seal ring 5 isimmediately preceded by the first valve portion 7 coming into closecontact with the first seal ring 4 to close communication between themetering chamber 6 and the interior of the gas chamber 1, apredetermined amount of the mixture of the gas and the contents trappedin the metering chamber 6 is sprayed from the gas spray valve.

[0008] A construction of gas spray valve that permits reuse of the gascontainer and the gas spray valve is described in Japanese PatentLaid-Open Publication No. Hei 11-301759. As shown in FIG. 10, the gasspray valve 10 includes a valve case 12 secured to an opening portion 11a of a gas container 11 and a valve pin 13 slidably received in thevalve case 12. Arranged within the valve case 12 are a first seal ring18, which comes into close contact with the outer surface of the valvepin 13 at a first position relatively close to the center of the gascontainer 11, and a second seal ring 19, which comes into close contactwith the outer surface of the valve pin 13 at a second positionrelatively far from the center of the gas container 11. A meteringchamber 21 is defined within the valve case 12 between the first sealring 18 and the second seal ring 19 for trapping a predetermined amountof gas prior to spraying. The valve pin 13 includes a gas conduit 22,which extends through the valve pin 13 from the top end thereofpositioned outside the gas container 11 and opens in the outer peripheryof the valve pin 13 at a position axially apart from the top end. Theopening of the gas conduit 22 on the outer periphery of the valve pin 13is arranged such that it is positioned above the second seal ring 19when the valve pin 13 is in its raised position and it is positionedbelow the second seal ring 19 within the metering chamber 21 when thevalve pin 13 is pushed down to a first stop position or further to asecond stop position at which the valve pin stops during its two-stepaction. The valve pin 13 further includes a first bypass portion and asecond bypass portion that, together with the inner surface of the firstseal ring 18, form a gap when the valve pin 13 is in the raised positionand in the second stop position, respectively, so that the interior ofthe gas container 11 communicates with the metering chamber 21 throughthis gap.

[0009] When the valve pin 13 is in the raised position in the gas sprayvalve of the above-described construction, the opening of the gasconduit 22 on the outer periphery of the valve pin 13 is positionedabove the second seal ring 19. As a result, communication between thegas conduit 22 and the metering chamber 21 is closed, whereas themetering chamber 21 remains in communication with the interior of thegas container 11 through the first bypass portion of the valve pin 13.When the valve pin 13 is pushed into the first stop position, the firstseal ring 18 closes communication between the gas container 11 and themetering chamber 21, and the opening of the gas conduit 22 on the outerperiphery of the valve pin 13 is positioned within the metering chamber21. As a result, the predetermined amount of the gas trapped in themetering chamber 21 is sprayed out from the gas container 11 through thegas conduit 22. When it is desired to inject or refill the gas into thegas container 11, a gas injector is connected to the valve pin 13 andthe valve pin 13 is pushed into the second stop position. This causesthe opening of the gas conduit 22 on the outer periphery of the valvepin 13 to move into the metering chamber 21 and brings the meteringchamber 21 into communication with the interior of the gas container 11through the second bypass portion of the valve pin 13. As a result, thegas is injected from the gas injector, through the metering chamber 21and the second bypass portion, into the gas container 11.

[0010] When a high-pressure gas such as liquid carbon dioxide is used asa propellant for the spray apparatus, the gas container and the gasspray valve must be of considerable strength to ensure safety. To thisend, more materials need to be used to construct the gas container andthe gas spray valve as compared to the conventional spray apparatus,which utilizes chlorofluorocarbon propellant. Accordingly, it is notdesirable, in view of efficient use of resources, to make the sprayapparatus disposable, which is the case with conventional sprayapparatuses. Nevertheless, the above-mentioned gas spray apparatusdescribed in Japanese Patent Laid-Open Publication No. Hei 8-141450 doesnot incorporate any structure that permits recharging of the gascontainer with the gas and contents, and therefore, the gas containersand the gas spray valves of these gas spray apparatuses must bediscarded after use.

[0011] Accordingly, it is an objective of the present invention toprovide a novel gas spray valve, which is not only simpler, stronger andmore durable than conventional spray valves, but also has a structuresuitable for industrial production while permitting recharging of thegas container after use, and thus, efficient use of natural resources,without leading to increased production costs. It is another objectiveof the present invention to provide an injection adapter for use withthe gas spray valve that facilitates recharging of the gas.

[0012] In general, the nozzle of the gas spray valve must be pushed intowhen acted upon by a force of 3 kgf or less so that the gas spray valvecan be manipulated with hands and fingers. When a high-pressure gas suchas liquid carbon dioxide is used as a propellant for the sprayapparatus, the magnitude of the force required to push the nozzle isproportional to the cross-sectional area of the valve pin upon which thepressure of the high-pressure gas is exerted. For this reason, thediameter of the valve pin is preferably Φ2.5 or less when liquid carbondioxide propellant is used. Although valve pins with a larger diametermay be used by employing a spring or the like to reduce the forcerequired to push the nozzle, the use of a spring makes the structure ofthe spray valve complex and leads to increased production costs.

[0013] With the diameter of Φ2.5 or less, the valve pin as disclosed inJapanese Patent Laid-Open Publication No. Hei 11-301759 may becomesusceptible to bending or breaking when subjected to a larger force dueto its reduced strength and rigidity, which results from the v-shapedgroove formed to serve as a bypass for allowing the gas into themetering chamber or for permitting recharging of the gas container withthe gas and desired contents. This can lead to faulty operation ormalfunction of the spray apparatus.

[0014] In addition to the gas conduit for allowing the gas and thecontents to be sprayed out, the valve pin includes the two V-shapedgrooves. Further, to prevent valve pin to flounce off of the containeror to restrict the raised position of the valve pin to allow desiredcontents such as gas to flow into the metering chamber from gascontainer, the stopper flange is configured at the bottom of valve pinat closer position to the center of gas container. Because such aunworkable gap process is required, the process is much complicated thatrequires long process time. Since the stopper flange is also required,use of various tools is also required.

[0015] Furthermore, the gas spray valve includes in the portion toreceive the valve pin two grooves to receive respective seal rings andanother groove to serve as the metering chamber. Since the valve pin hasa diameter of Φ2.5 or less as described above, the size of the bore forreceiving the valve pin is correspondingly small. In practice, it isdifficult to form the grooves through the relatively small bore. Forthis reason, the structure of the gas spray valve is not suitable forindustrial production.

DISCLOSURE OF THE INVENTION

[0016] In order to accomplish the objects, according to the invention asclaimed in claim 1, a gas spray valve includes a valve case secured toan opening portion of a gas container; a valve pin being outer portionsmaller in diameter than the inner portion of the same, slidablyreceived in the valve case; a first seal ring and a second seal ringarranged within the valve case, the first seal ring coming into closecontact with an outer periphery of the valve pin at a first positionthat is relatively close to the center of the gas container and thesecond seal ring coming into close contact with the outer periphery ofthe valve pin at a second position that is relatively far from thecenter of the gas container; and a metering chamber formed between thefirst seal ring and the second seal ring to trap a predetermined amountof gas prior to spraying. The gas spray valve is configured such thatthe valve pin includes a gas conduit extending therethrough from a topend thereof that is positioned outside the gas container to a point onan outer periphery thereof that is axially apart from the top end, withan opening of the gas conduit on the outer periphery of the valve pinbeing arranged such that it is positioned above the second seal ringwhen the valve pin is in its raised position, it is positioned below thesecond seal ring within the metering chamber when the valve pin ispushed into a first and second stop position. The valve pin furtherincludes a gas supply passage extending from a bottom end thereof thatis positioned within the gas container to a point on the outer peripheryof valve pin with larger diameter that is axially apart from the bottomend. One of the openings of the gas supply passage that is on the outerperiphery of the valve pin is arranged such that, when the valve pin isin the raised position, it is positioned above the first seal ringwithin the metering chamber, and only when the valve pin is pushed intothe second stop position, the portion with smaller diameter of valve pinis positioned within the gas container that is positioned below thefirst seal ring to open communication between the interior of the gascontainer and the metering chamber.

[0017] The present invention is such that, when the valve pin is in itsraised position, the opening of the gas conduit on the outer peripheryof the valve pin is positioned above the second seal ring to closecommunication between the gas conduit and the metering chamber, and theopening of the gas supply passage on the outer periphery of the valvepin is positioned above the first seal ring within the metering chamberto maintain communication between the metering chamber and the interiorof the gas container. When the valve pin is pushed into the first stopposition, the first seal ring closes communication between the interiorof the gas container and the metering chamber while the opening of thegas conduit on the outer periphery of the valve pin moves into themetering chamber. As a result, the predetermined amount of the gastrapped in the metering chamber is sprayed out from the gas containerthrough the gas conduit.

[0018] Upon injection of the gas into the gas container, the valve pinis connected to a gas injector and is pushed into the second stopposition. This causes the opening of the gas conduit on the outerperiphery of the valve pin to move into the interior of the meteringchamber, and the portion with smaller diameter of valve pin is pusheddown into the gas container that is positioned below the first sealring, then the obstruction is broken between the valve pin and the firstseal ring, as the result, allowing the gas to flow from the gas injectorinto the gas container through the metering chamber.

[0019] In the valve pin in accordance with the present invention, thetwo v-shaped grooves can be dispensed with. As described above, the twogrooves are disclosed in Japanese Patent Laid-Open Publication No. Hei11-301759 and each serve as a bypass passage to permit the gas flow whenthe metering chamber is charged with the gas or when the gas containeris refilled.

[0020] In the invention as claimed in claim 1, the invention as claimedin claim 2 is the gas spray valve in which grooves for holding the firstand the second seal rings in place and for serving as the meteringchamber are formed simply by partially enlarging a guide bore of thevalve case to receive the valve pin, inserting into the enlargedportions of the bore components with simple construction that is formedseparately from the valve case, and calking the valve case both at theupper end and the lower end thereof, rather than by forming grooves onan inner surface of the guide bore of the valve case.

[0021] In the invention as claimed in claim 1 and 2, the invention asclaimed in claim 3 is the valve pin in which a lateral bore and a gassupply passage formed on the valve pin with larger diameter aredisplaced with chamfered or notched conduit that is formed on the outerperiphery of said valve pin.

[0022] In the invention as claimed in claim 1, 2 and 3, the invention asclaimed in claim 4 is one having a nozzle head attached to the top endof the valve pin. The nozzle head includes a stopper face forrestricting the displacement of the valve pin to the first stopposition.

[0023] In this manner, the gas is sprayed out from the gas container inconstant amounts by pushing the nozzle head until stopped by the stopperface.

[0024] The present invention as claimed in claim 5 provides an injectionadapter attached to the top end of the valve pin when gas is injectedinto the gas container through the gas spray valve as claimed in one ofclaims 1 to 4. The injection adapter includes a stopper face forrestricting displacement of the valve pin to the second stop position.

[0025] In this manner, the gas can be injected into the gas container bypushing the injection adapter until stopped by the stopper face.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1 is a cross-sectional view showing a first embodiment of agas spray valve in accordance with the present invention.

[0027]FIG. 2 is a cross-sectional view showing the same gas spray valvewith a nozzle head pushed.

[0028]FIG. 3 is a cross-sectional view showing the same gas spray valvehaving an injection adapter attached thereto. The injection adapter isshown pushed to permit delivery of desired contents and high-pressuregas from a gas injector.

[0029]FIG. 4 is a cross-sectional view showing a second embodiment ofthe gas spray valve in accordance with the present invention.

[0030]FIG. 5 is a cross-sectional view showing the same gas spray valvewith a nozzle head pushed.

[0031]FIG. 6 is a cross-sectional view showing the same gas spray valvehaving an injection adapter attached thereto. The injection adapter isshown pushed to permit delivery of desired contents and high-pressuregas from a gas injector.

[0032]FIG. 7 is a cross-sectional view showing a third embodiment of thegas spray valve in accordance with the present invention.

[0033]FIG. 8 is a cross-sectional view showing a fourth embodiment ofthe gas spray valve in accordance with the present invention.

[0034]FIG. 9 is a cross-sectional view showing a conventional gas sprayvalve as prior art.

[0035]FIG. 10 is a cross-sectional view showing another type ofconventional gas spray valve as prior art.

BEST MODE FOR CARRYING OUT THE INVENTION

[0036] Several embodiments of the present invention will now bedescribed with reference to FIGS. 1 through 10.

[0037] First, a first embodiment of the present invention is describedwith reference to FIGS. 1, 2 and 3.

[0038]FIGS. 1, 2 and 3 show a spray apparatus employing a gas sprayvalve 101 in accordance with the present invention. The spray apparatusessentially consists of a gas container 102, which containshigh-pressure gas such as liquid carbon dioxide along with desiredcontents such as a medical agent, and the gas spray valve 101hermetically secured to an opening portion 102 a of the gas container102.

[0039] The gas spray valve 101 includes a valve case 103 secured bycalking to the opening portion 102 a of the gas container 102 and avalve pin 104 slidably retained in the valve case 103. A nozzle head 112is secured to the valve pin 104 on the top end thereof projects abovethe valve case 103. The nozzle head serves both as a nozzle and as apush button.

[0040] The valve case 103 includes a guide bore 113 axially extendingthrough the center thereof. The valve pin 104 is inserted through theguide bore 113. A pair of annular grooves 114 and 115 are formed on theinner surface of the guide bore 113 at a first position relatively closeto the center of the gas container 102 and at a second positionrelatively far from the center of the gas container 102, respectively.The annular grooves 114 and 115 receive a first seal ring 106 and asecond seal ring 108, respectively. The first seal ring 106 and thesecond seal ring 108 are each made of an elastic material. An annularrecess 116 is formed in the guide bore 113 substantially at the centerthereof. The annular recess 116 forms part of a space formed between theseal rings 106 and 108 that serves as a metering chamber 110 fortrapping a predetermined volume of the gas before it is sprayed out.

[0041] The valve pin 104 includes a gas conduit 111 extending through aportion thereof that can project above the valve case 103. The gasconduit 111 opens in an end surface of the valve pin 104 and in theouter periphery of the valve pin 104 at a position axially apart fromthe end surface. Specifically, the gas conduit 111 consists of an axialbore 111 a extending vertically from the end surface of the valve pin104 and an orifice 111 b extending radially from the bottom portion ofthe axial bore 111 a to the outer periphery of the valve pin 104. Theaxial bore 111 a has a relatively large diameter and the orifice 111 bhas a diameter smaller than that of the axial bore 111 a. The orifice111 b determines the amount of gas sprayed out from the gas spray valve101 per unit time. The size of the orifice must therefore be properlydetermined depending on the desired amount of the gas sprayed per unittime. The orifice 111 b is arranged at the predetermined position on theperiphery of the valve pin 104 such that it is positioned above thesecond seal ring 108 when the valve pin 104 is in its raised position,is positioned below the second seal ring 108 within the metering chamber110 when the valve pin 104 is pushed into a first and second stopposition, which will later be described.

[0042] Also, the valve pin 104 being outer portion smaller in diameterthan the inner portion of the same arranged within the gas container102, has valve pin stopper flange 117 as being the place where gap indiameter starts, which restrict the upward slide of valve pin 104.Further, the valve pin 104 acts upon by the pressure of the gas withinthe gas container 102 on the cross section area of the outer portionsmaller in diameter so that it is always urged upward.

[0043] The valve pin 104 further includes a gas supply passage 118extending therethrough from the bottom end thereof positioned inside thegas container 102 to a point on the outer periphery of the valve pinwith larger diameter 104 b axially apart from the bottom end.Specifically, the gas supply passage 118 consists of an axial bore 118 aextending vertically from the bottom end of the valve pin 104 and alateral bore 118 b extending radially to connect the bottom portion ofthe axial bore 118 a to the outer periphery of the valve pin 104. Thelateral bore 118 b is arranged at a position on the periphery of thevalve pin with larger diameter 104 b such that, with the valve pin 104in the raised position, it is positioned above the first seal ring 106within the metering chamber 110 so that the lateral bore 118 b, togetherwith the axial bore 118 a, connects the interior of the gas container102 to the metering chamber 110 inside the first seal ring 106. Insecond stop position, the portion with smaller diameter 104 a of valvepin 104 is pushed down below the first seal ring 106, so that theobstruction is broken between the valve pin and the first seal ring 106and the communication between the interior of the gas container 102 andthe metering chamber 110 is opened.

[0044] The first stop position of the valve pin 104 is a relativelyshallow position at which the valve pin 104 stops when the nozzle head112 is pushed to spray the gas. Once the valve pin 104 has been pushedinto the first stop position, further displacement of the valve pin 104is restricted by mean of a stopper face 120, or the bottom surface ofthe nozzle head 112, abutting a top surface 103 a of the valve case 103.The second stop position of the valve pin 104 is a relatively deepposition at which the valve pin 104 stops when gas is injected from thetop end of the valve pin 104 into the gas container 102. As shown inFIG. 3, upon injection of the gas, the nozzle head 112 is replaced by aninjection adapter 121 of a gas injector, which restricts furtherdisplacement of the valve pin 104 once the valve pin 104 has been pushedinto the second stop position. The injection adapter 121 includes a sealring 122 that comes in close contact with the outer periphery of thevalve pin 104 and a bottom surface to serve as a stopper face 123. Thestopper face 123 abuts the top surface 103 a of the valve case 103 torestrict further displacement of the valve pin 104 once the valve pin104 has been pushed into the second stop position with the injectionadapter 121 attached to the top end of the valve pin 104.

[0045] When the gas spray valve 101 constructed in the above-describedmanner is in its steady state without the nozzle head 112 being pushed,the valve pin 104, acted upon by the gas pressure within the gascontainer 102, is held in the raised position as shown in FIG. 1. Inthis state, the orifice 111 b of the valve pin 104 is positioned abovethe second seal ring 108 to close communication between the gas conduit111 and the metering chamber 110. Also, the lateral bore 118 b providedin the lower portion of the valve pin with larger diameter 104 d ispositioned above the first seal ring 106 so that the metering chamber110 communicates with the interior of the gas container 102 through thegas supply passage 118 including the lateral bore 118 b.

[0046] When the nozzle head 112 is pushed, the lateral bore 118 b in thelower portion of the valve pin 104 is displaced downward to below thefirst seal ring 106 as shown in FIG. 2, so that the first seal ring 106closes communication between the interior of the gas container 102 andthe metering chamber 110. Subsequently, the orifice 111 b of the valvepin 104 moves to below the second seal ring 108 into the meteringchamber 110 so that the predetermined amount of the gas and the contentswithin the metering chamber 110 is sprayed out from the gas container102 through the gas conduit 111 of the valve pin 104. The downwarddisplacement of the valve pin 104 is restricted to the first stopposition by the stopper face 120 of the nozzle head 112 abutting the topsurface 103 a of the valve case 103.

[0047] When the gas container 102 is emptied of the gas and the contentsthrough the use as described above, the nozzle head 112 is removed fromthe top end of the valve pin 104 and the injection adapter 121 of thegas injector is attached instead. The injection adapter 121 is thenpushed until the stopper face 123 comes into contact with the topsurface 103 a of the valve case 103 as shown in FIG. 3 to allow thedesired contents to be supplied from the gas injector along withhigh-pressure gas. The pushing motion of the injection adapter 121causes the valve pin 104 to be displaced downward into the second stopposition so that the orifice 111 b is positioned below the second sealring 108 and opens within the metering chamber 110, and the portion withsmaller diameter 104 a of valve pin 104 is pushed down below the firstseal ring 106, the obstruction is broken between the valve pin and thefirst seal ring 106 and the communication between the interior of thegas container 102 and the metering chamber 110 is opened. As a result,the gas conduit 111 of the valve pin 104 comes into communication withthe interior of the gas container 102 through the metering chamber 110to allow the contents and the gas supplied from the gas injector to beinjected into the gas container 102.

[0048] Once injection of the gas and the contents into the gas container102 has been completed and the injection adapter 121 is released fromthe position for injection, the valve pin 104, acted upon by the gaspressure within the gas container 102, returns to the raised position sothat the orifice 111 b is positioned above the second seal ring 108 toclose communication between the gas conduit 111 and the metering chamber110. The injection adapter 121 is then removed from the top end of thevalve pin 104 and the nozzle head 112 is mounted back on. This completesrefill of the container with the gas and the contents.

[0049] In summary, the gas spray valve 101 in accordance with thepresent invention, despite its unusually simple structure, permitsrefill of the gas container 102 with the gas and the contents andthereby permits reuse of the gas container 102 and the gas spray valve101. Thus, the gas spray valve can make efficient use of naturalresources without a considerable increase in the production costs. Also,the gas spray valve 101 in accordance with the present inventiondispenses with the v-shaped groove in the valve pin 104 such as thatdisclosed in Japanese Patent Laid-Open Publication No. Hei 11-301759.The v-shaped groove, formed on the valve pin to permit charging of themetering chamber with the gas or the like or to serve as a bypasspassage for refilling the gas container with the gas and the contents,makes it necessary for the valve pin to have the preferred diameter ofΦ2.5 or less to facilitate operation of the valve. As a result, thestrength of the valve pin is reduced, as is its rigidity, making thevalve pin susceptible to faulty operation or malfunction caused bybending and breaking of the valve pin by operative forces. Without suchv-shaped grooves, the strength and the rigidity of the valve pin 104 areensured in the gas spray valve 101 of the present invention, as is thereliable and safe operation of the valve pin 104.

[0050] The gas spray valve disclosed in Japanese Patent Laid-OpenPublication No. Hei 11-301759 further facilitate stopper flange at thebottom end of the valve pin to prevent the valve pin to pushed out ofthe gas container and to restrict the raised position of the valve pinwhen injecting the contents such as gas in the gas container into themetering chamber. Unlike the above, the gas spray valve 101 of thepresent invention dose not require provision of stopper flange and thev-shaped groove, the valve pin can be manufactured through fewerprocesses using fewer tools, making the gas spray valve less expensive.

[0051] Next, a second and third embodiment of the present invention isdescribed with reference to FIGS. 4 to 8. Construction of thisembodiment is essentially the same as that of the first embodimentdescribed above with reference to FIGS. 1, 2 and 3, except for theannular groove 114 (first seal ring portion) and the annular groove 115(second seal ring portion), each formed on the valve case 103, theannular recess 116 to serve as the metering chamber 110 and the gassupply passage 118 including the axial bore 118 b formed on the portionwith larger diameter 104 b of valve pin 104.

[0052] In the following description, parts identical to those in thefirst embodiment are denoted by the same numerals, and description ofthese parts will not be repeated.

[0053] In the second embodiment of the present invention shown in eachof FIGS. 4, 5 and 6, an annular groove 114 (a first seal ring portion)for receiving a first seal ring 106 is defined by a first seal ringguide A 105 placed below the first seal ring 106 and a first seal ringguide B 107 placed above the first seal ring 106. A valve case 103 iscalked at a lower end 103 b to secure the first seal ring guide A 105.Likewise, an annular groove 115 (a second seal ring portion) forreceiving a second seal ring 108 is defined by an annular rib 119 placedbelow the second seal ring 108 and formed as a part of the valve case103, and a second seal ring guide 109 placed above the second seal ring108. The valve case 103 is calked at an upper end 103 a to secure thesecond seal ring guide 109. An annular recess 116 to serve as a meteringchamber is also defined by the annular rib 119 of the valve case 103 andthe first seal ring guide B 107.

[0054] Unlike the gas spray valve of the first embodiment, in whichgrooves must be formed inside the guide bore of the valve case 103 toreceive the valve pin 104 so that they can serve as the annular grooves114 and 115 and as the annular recess 116, or the metering chamber 110,the gas spray valve in this embodiment does not require formation oftechnically demanding groove features and can be constructed simply byboring into the valve case 103 from either end thereof, inserting intothe bore the first seal ring guide A 105, the first seal ring guide B107, the first seal ring 106 and the second seal ring 108, these aresimply formed separately, and then calking the valve case 103 both atthe upper end 103 a and at the lower end 103 b thereof. Such simpleconstruction of the gas spray valve of the second embodiment not onlycontributes to the productivity during production, but also permits asignificant cost reduction.

[0055] In the third embodiment of the present invention shown in FIG. 7,the gas supply passage 118 including the lateral bore 118 b formed onthe portion with larger diameter 104 b of valve pin 104 of the first andsecond embodiment is replaced by a notch conduit 124 on the periphery ofthe portion with the larger diameter 104 b of valve pin 104 having achamfered form.

[0056] Further, in the fourth embodiment of the present invention shownin FIG. 8, the gas supply passage 118 including the lateral bore 118 bformed on the portion with larger diameter 104 b of valve pin 104 of thefirst and second embodiment is replaced by a notch conduit 125 on theperiphery of the portion with the larger diameter 104 b of valve pin 104having a key groove form.

[0057] In the case of the gas spray valve of the third and fourth.embodiment, the gas supply passage 118 including the lateral bore 118 bformed on the portion with larger diameter 104 b of valve pin 104 of thefirst and second embodiment is replaced by a notch conduit having achamfered form or key groove form on the periphery of the portion withthe larger diameter 104 b of valve pin 104, and therefore, the gas sprayvalve in these embodiments do not require a long machining time to formfine groove as in the case of the first and second embodiment. Further,the strength and rigidity of the valve pin 104 can be maintained andthis leads to increased productivity, and thus, to a significant costreduction.

[0058] Industrial Applicability

[0059] As set forth, the invention as claimed in claim 1 provides anovel spray gas valve including a valve pin, being outer portion of agas container smaller in diameter than an inner portion of the same,having a gas conduit extending therethrough from a top end thereof thatis positioned outside the gas container to a point on the outerperiphery thereof that is axially apart from the top end. An opening ofthe gas conduit on the outer periphery of the valve pin is arranged suchthat it is positioned above the second seal ring when the valve pin isin its raised position and it is positioned below the second seal ringwithin the metering chamber when the valve pin is pushed into a firstand second stop position. The valve pin further includes a gas supplypassage extending from a bottom end thereof that is positioned withinthe gas container to a point on the outer periphery of the valve pinthat is axially apart from the bottom end. An opening of the gas supplypassage on the outer periphery of the valve pin is arranged such that,when the valve pin is in the raised position, it is positioned above thefirst seal ring within the metering chamber, and only when the valve pinis pushed into the second stop position, the portion with largerdiameter of valve pin which comes into close contact with the secondseal ring is positioned below the first seal ring so that the portionwith smaller diameter of valve pin is positioned within the gascontainer and is positioned below the first seal ring, as the result,the obstruction is broken between the valve pin and the first seal ringto open communication between the interior of the gas container and themetering chamber.

[0060] In this manner, the predetermined amount of the gas trapped inthe metering chamber is sprayed out from the gas container through thegas conduit of the valve pin by pushing the valve pin into the firststop position. In addition, by pushing the valve pin further into thesecond stop position with the gas injector connected to the top end ofthe valve pin, the gas conduit is brought into communication with theinterior of the gas container so that the gas can be injected into thegas container in a reliable manner.

[0061] Thus, despite its unusually simple structure, the presentinvention permits recharging of the gas container of the used sprayapparatus through the gas spray valve and thereby permits reuse of thegas container and the gas spray valve. Ultimately, the gas spray valveaccording to the present invention facilitates efficient use of naturalresources without a considerable increase in the production costs.

[0062] As disclosed in Japanese Patent Laid-Open Publication No. Hei11-301759, the v-shaped groove, which is formed on the valve pin topermit charging of the metering chamber with the gas or the like or toserve as a bypass passage for refilling the gas container with the gasand the contents, makes it necessary for the valve pin to have thepreferred diameter of Φ2.5 or less to facilitate operation of the valve.As a result, the strength of the valve pin is reduced, as is itsrigidity, making the valve pin susceptible to faulty operation ormalfunction caused by bending and breaking of the valve pin by operativeforces. However, the gas spray valve in accordance with the presentinvention, which dispenses with the v-shaped groove in the valve pin,can ensure the strength and the rigidity of the valve pin, therebyensuring reliable and safe use of the valve pin.

[0063] The gas spray valve disclosed in Japanese Patent Laid-OpenPublication No. Hei 11-301759 further facilitate stopper flange at thebottom end of the valve pin to prevent the valve pin to pushed out ofthe gas container and to restrict the raised position of the valve pinwhen injecting the contents such as gas in the gas container into themetering chamber. Unlike the above, the present invention dose notrequire provision of stopper flange and the v-shaped groove, the valvepin can be manufactured through fewer processes using fewer tools,making the gas spray valve less expensive.

[0064] In the invention as claimed in claim 1, the invention as claimedin claim 2 provides the grooves for holding the first and the secondseal rings in place and for serving as the metering chamber, formedsimply by partially enlarging a guide bore of the valve case to receivethe valve pin, inserting into the enlarged portions of the borecomponents with simple construction that is formed separately from thevalve case, and calking the valve case both at the upper end and thelower end thereof, rather than by forming technically demanding groovesinside on an inner surface of the guide bore of the valve case toreceive the valve pin. Such simple construction is of sufficientstrength and can readily be manufactured. This leads to increasedproductivity, and thus, to a significant cost reduction.

[0065] In the invention as claimed in claim 1 or 2, the invention asclaimed in claim 3 is the valve pin in which an lateral bore and a gassupply passage of the valve pin with larger diameter are displaced withchamfered or notched conduit that is formed on the outer periphery ofsaid valve pin. Therefore, the gas spray valve of the invention does notrequire a long machining time to form fine groove as in the case of thefirst and second embodiment. Further, the strength and rigidity of thevalve pin 104 can be maintained and this leads to increasedproductivity, and thus, to a significant cost reduction.

[0066] In the invention as claimed in claims 1 to 3, the invention asclaimed in claim 4 provides a nozzle head to be attached to the top endof the valve pin including a stopper face for restricting thedisplacement of the valve pin to the first stop position. In thismanner, during normal use, the gas is always sprayed out from the gascontainer in constant amounts by simply pushing the nozzle head untilstopped by the stopper face.

[0067] The invention as claimed in claim 5 is an injection adapterattached to the top end of the valve pin when gas is injected into thegas container through the above-described gas spray valve in accordancewith the invention as claimed in one of claims 1 to 4. The injectionadapter includes a stopper face for restricting displacement of thevalve pin to the second stop position. In this manner, the gas can beinjected into the gas container in a reliable manner by simply attachingthe injection adapter to the top end of the valve pin and pushing theinjection adapter until stopped by the stopper face.

1. A gas spray valve, including: a valve case secured to an openingportion of a gas container; a valve pin slidably received in the valvecase; a first seal ring and a second seal ring arranged within the valvecase, the first seal ring coming into close contact with an outerperiphery of a larger diameter portion of the valve pin at a firstposition that is relatively close to the center of the gas container,the second seal ring coming into close contact with the outer peripheryof a smaller diameter portion of the valve pin at a second position thatis relatively far from the center of the gas container; a meteringchamber formed between the first seal ring and the second seal ring totrap a predetermined amount of gas prior to spraying; and a diameter gapbetween the larger diameter portion and the smaller diameter portion ofthe valve pin is used as a stopper face to restrict the raised positionof the valve pin, the gas spray valve characterized in that, the valvepin includes a gas conduit extending therethrough from a top end thereofthat is positioned outside the gas container to a point on an outerperiphery thereof that is axially apart from the top end, with anopening of the gas conduit on the outer periphery of the valve pin beingarranged such that it is positioned above the second seal ring when thevalve pin is in its raised position, it is positioned below the secondseal ring within the metering chamber when the valve pin is pushed intoa first and second stop position; the valve pin further includes a gassupply passage extending from a bottom end thereof that is positionedwithin the gas container to a point on the outer periphery that isaxially apart from the bottom end, an opening of the gas supply passageon the outer periphery of the valve pin being arranged such that, whenthe valve pin is in the raised position, it is positioned above thefirst seal ring within the metering chamber, and only when the valve pinis pushed into the second stop position, the portion with smallerdiameter of valve pin is positioned within the gas container that ispositioned below the first seal ring to open communication between theinterior of the gas container and the metering chamber.
 2. The gas sprayvalve as claimed in claim 1, characterized in that grooves for holdingthe first seal ring and the second seal ring in place and for serving asthe metering chamber are formed simply by partially enlarging a guidebore of the valve case to receive the valve pin, inserting into theenlarged portions of the bore components with simple construction thatis formed separately from the valve case, and calking the valve caseboth at the upper end and the lower end thereof, rather than by forminggrooves on an inner surface of the guide bore of the valve case.
 3. Thegas spray valve as claimed in claim 1 or 2, characterized in that thegas supply passage of the valve pin with larger diameter is composed ofthe chamfered or notched conduit that is formed on the outer peripheryof said valve pin.
 4. The gas spray valve as claimed in any one ofclaims 1 to 3, characterized in that the gas spray valve furthercomprises a nozzle head attached to the top end of the valve pin, andthe nozzle head includes a stopper face for restricting the displacementof the valve pin to the first stop position.
 5. An injection adapterattached to the top end of the valve pin when gas is injected into thegas container through the gas spray valve as claimed in any one ofclaims 1 to 4, characterized in that the injection adapter includes astopper face for restricting displacement of the valve pin to the secondstop position.